Self-cleaning air precleaner



Dec. 8, 1953 s. c. HETH SELF-CLEANING AIR PRECLEANER 3 Sheets-Sheet 1 Filed July 15, 1949 INVENTOR. C. HETH Dec. 8, 1953 s. c. HETH 2,661,310

SELF-CLEANING AIR PRECLEANER Filed July 15, 1949 5 Sheets-Sheet 2 INVENTOR. Z fi 7 JHseMn/v C. HETH BY W I Dec. 8, 1953 5, HETH 2,661,810

I SELF-CLEANING AIR PRECLEANER Filed July 15, 1949 I 3 Sheets-Sheet 5 Patenteci Dec. 8, 1953 SELF-CLEANIN G AIR PRECLEANER Sherman C. Heth, Racine, Wis., assignor to J. 1. Case Company, Racine, Wis., a corporation of Wisconsin Application July 15, 1949, Serial No. 104,969

This invention relates to an air pie-cleaner and especially to the type used with internal combustion engines of farm implements.

An object is to provide an air pie-cleaner for the purpose of preventing chaff and other debris from entering the air cleaner, the latter being adapted merely to remove fine dust from the air before it reaches the carburetor.

A further object of this invention is to provide an air pro-cleaner that will not substantially restrict the flow of air to the carburetor.

Another object is to provide an air pro-cleaner that will not allow water to enter the conduit leading to the carburetor.

' A further object is to provide an air precleaner that is positive in its operation and not easily disabled.

Another object is to provide an air pro-cleaner which has a horizontal screen from which chaif Will tend to drop thus enlisting the aid of gravity in its operation.

A further object is to provide an air precleaner that will automatically and continuously release chaff and other debris from the screen when the engine is in operation.

A further object is to provide an air precleaner that will increase the effective pre-cleaning operation as the engine speed increases,

Further objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawings wherein a satisfactory embodiment of the invention is shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention.

Referring to the drawings-- Fig. 1 shows an assembly of the pre-cleaner, air cleaner and carburetor;

Fig. 2 shows a plan view of the pre-cleaner with parts broken away;

Fig. 3 shows a section at 3-3 of Fig. 2;

Fig. i is a plan view of the rotor removed from the pre-cleaner casing;

Fig. 5 is a section taken at 5-5 of Fig. 4;

Fig. 6' is a section taken at 8-8 of Fig. 4;

Fig. 7 is a section taken at 1-1 of Fig. 3;

Fig. 8 is a fragmentary plan view of a modifled form of the invention;

Fig. 9 is a fragmentary side view of the modification and Fig. 10 is a bottom view thereof.

A serious problem encountered in the operation of farm implements is the prevention of chart and other debris, prevalent in the air sur- 1 Claim. (01. 183-52) rounding the intake of the carburetor from entering therein. To allow these large particles to enter the conduit to the carburetor would ultimately result instoppage of the engine. At the present time, air cleaners of the oil bath and other types are employed to clean the air of dust and fine particles before it enters the carburetor. These air cleaners are not designed to remove such large particles as chair and other debris 3 from the air, owing to the nature of such cleaners. To allow such particles to enter the air cleaner would be to render the latter inoperative in a comparatively short time due to choking.

The function of the air pre-cleaner is to provide means whereby the chaff and other debris may previously be screened from the air and deposited on the ground and not be allowed to reach the air cleaner.

Chafi screens are presently employed for preventing chaff and large particles from getting into the carburetor conduit. These screens usually have manually operated means to remove the. chair and require the constant attention of the operator. For efficient operation, it is necessary to provide automatically-operating means for removing the chaff from the screen or" the pre-cleaner so that constant attention of the operator will not be required.

It is believed that this invention accomplishes the objects above enumerated and it will now be described.

The invention, in this instance comprises a casing mounted upon an air inlet conduit, and having a screen. A rotor having oblique vanes is-positioned in the casing in close proximity to the screen and is rotated by the impingement of air against the vanes, such flow being induced by the engine intake. The rotor must be sufficiently close to the screen to substantially completely interrupt the flow of air through the screen. As the imperforate segment of the rotor passes successive areas of the screen, the flow of air through thelatter is interrupted over that immediate area, thus allowing any chaff previously deposited and adhering to the screen at that point to fall away; this process continues as long as the engine operates.

Referring to Fig. l, the air pre-cleaner P is mounted on the conventional air cleaner A which is in turn connected to the conventional carburetor C.

Referring to Figs. 2 to 7 inclusive, it comprises a casing which is closed against the entrance of rain, snow, etc., and which can boot any convenient shape, preferably cylindrical. Casing I 0 hasan outwardly directed flange H for the purpose of accommodating fastening means which secure the members of the pre-cleaner together thereby providing a convenient means of disassembling when necessary to clean and service it. Customary locating pins [a and 550 are provided to maintain axial alignment between the components of the casing.

A support member l2 shown in Figs. 2:. 3 and 7, extends to the full diameter of the flange H and serves to support the casing 10. Member i2 is formed with a plurality of apertures l3 leaving arms 14 terminating in a ring 15. An annular reinforcing ring It may be used; to stiffen the ring 15' and to insure that a reasonably good contact is maintained between flange I I and ring [5. A plurality of wing bolts IT, or any other convenient form of fastening may be employed to secure the casing In to the support member i2. The fastening means should be of a type that will allow convenient removal of casing 10 for the purpose of cleaning.

A boss i8 is formed downwardly in the center of support member l2 and a bearing memher 9 is pressed therein. Bearing 19- comprises a body portion 2a and a flange 2|. A V center 22 is provided and serves as a bearing to accommodate the shaft of the rotor which will be described later.

A circular screen 23 approximately the diameter of easing It serves to cover apertures [3. Screen 23 is preferably of wire screen, but may also be of sheet material having perforations, whichever is found most suitable. This screen is secured to ring l and arms is by spot welding or any other suitable method of fastening. Screen 23 terminates at 24 leaving an unobstructed passage for air thru the conduit 41. See Fig. 7.

Casing it in this instance has an upturned boss 25 which is co-axial with boss I8. Bearing member 26 is of similar construction to bearing member !9 but with the exception that bearing member 25 is threaded a snug fit into boss 25 so as to provide axial adjustment for the rotor shaft. Boss 25 may be provided with slits so as to frictionally hold the bearing 26 against turning owing to vibration. A slot is provided in bearing 26 for the reception of a screw driver when making adjustments. A V center 21 is provided to accommodate the shaft of the beforementioned rotor. Bearing members is and 26 are coaxial with casing H) for reasons that will appear later. It is not the intention to limit this invention to use of the type of bearings shown.

Any one of the various methods of journalling known to the art may be employed if found suitable, reliable and economical.

A rotor 28 in Figs. 2, 3 and 4 freely rotates within casing iii in close proximity to screen 23 and parallel thereto. The proximity to screen 23 being found by trial. Rotor 28 comprises segments 29 and so which are diametrically opposed in this instance, leaving spaces 31 and 32 intermediate segments 29 and 32. A plurality of oblique vanes 33 shown in Figs. 2, 3, 4 and 5 are formed upwardly in segment 3i? and can be of any number found suitable. vanes 33 are preferably placed in a radial position, although other positions may also be found suitable. A hub portion 35: is provided with openings 35, the purpose of which will be explained later. There are four such openings and these are defined by spokes 36. Spokes 36, in this instance, lie in the plane of segments 29 and 30. A boss 3'! is formed upwardly in rotor 28 at the axis thereof and which accommodates the rotor shaft and provides a central hub for the rotor 28.

Segment 29 is provided with an upstanding vane 38 shown in Figs. 2, 3, 4 and 6 and which is preferably at right angles to the plane of segment 29 and which serves as a bailie to dampen the speed of rotation of rotor 28. Vane 38 is in this instance made radial and should be of an area found suitable for the purpose. The area of vane 38 should be such as to allow rotor 28 to rotate at such speed as to allow chafi to drop from the screen 23 a sufiicient distance so as to be out of reach of the air stream and not be again drawn to the screen 23.

An auxiliary hub member 39 serves to support the rotor shaft and to strengthen the rotor. Hub member 39 comprises a ring portion 46 which coincides with hub portion 34. Extending upwardly and radially from ring portion 46 and integral therewith are four spokes 4H superimposed on and similar to spokes 38 with the exception that spokes ii form portions of a cone. Spokes ii terminate in a sleeve portion 42 which is co-axial with boss 3? and spaced at a distance am'ally from the plane of rotor 23 so as to provide adequate support for the latter.

A shaft 23 provides the rotative support for rotor 23. This shaft is provided with pointed ends lid and $5 in this instance, and which are journaled in V centers 22 and 27, respectively. Sleeve 52 is secured to shaft '13 in a suitable manner such as by pinning as shown at Rotor 23 is adjusted in assembly so as to rotate close to screen 23 for the most eflicient operation. Bearing member 26 is finally adjusted so that rotor 28 rotates freely when casing it is assembled on support member 12.

A conduit #7 preferably of cylindrical crosssection forms the means of support for the precleaner 1 and provides a passage for air from the latter to the air cleaner A (see Fig. i); the lat ter usually being of the oil bath type. A cone shaped member 23 is provided with a cylindrical collar (3'5 which is a close fit for conduit 47 and which may be welded or otherwise fastened to the conduit. A cone shaped portion 56 flares outwardly upwardly terminating in a ring 5!. Ring forms the support for the complete air pre-cleaner. In assembly the four arms i of support member i2 are spotwelded to ring iii at points 52 (Fig. 7), so that the axes of conduit 4i and shaft 43 coincide. Screen is spotwelded to ring 5% at points 53 so as to prevent the passage of chafi and other debris into the conduit 4': at this point.

The conduit in this instance is assembled vertically to the air inlet or" an air cleaner A of the oil bath or other type. The diameter of conduit il can be such as to accommodate the conventional cleaner, and the length of the conduit can be such that is suitable for the particular application. The cycle or" operation of the air ire-cleaner 15 as follows: When the engine is operating it creates a constant flow of airas shown by the arrows in Figs. 1 and 3 through the screen 23 and downwardly into conduit 3?, part of the air flowing freely through the screen at spaces 3i and and part flowing through spaces As this flow of air impinges against oblique vanes the force imparted to the rotor 28 rotates the latter in the direction of the arrow (Fig. 4), the passing through the openings 3 i 32 and .54, and down into conduit 4?.

A rotor 28 rotates, the segments 29 and 30 interfere momentarily, over successive portions, with the flow of air through screen 23. When such interference occurs, any chaff adhering to screen 23 falls away over that area thereby leaving a clean screen in the path of the segments 29 and 30, through which air may freely pass. The air passes through screen 23 at constantly shifting segmental openings 3| and 32. As rotation of rotor 28 results in these segmental openings being uncovered over successive portions, it will be understood that a constant cycle of cleaning takes place. The thoroughness of the cleaning operation will depend on the fineness of the screen, the rate of flow of air passing therethrough,and the rate of rotation of rotor 28. As rotor 28 rotates, the resistance to rotation offered by the baille 38 prevents the rotor from turning at an excessive speed which excess would impair the efficiency of the pre-cleaner in that the chaff would not be released from the screen a sufficient distance to avoid being repeatedly drawn to the screen, thus impeding the free flow of air.

Some air pre-cleaner installations may require that the air conduit be connected to the casing at the top as shown in Figs. 8, 9 and 10. Referring to the drawings, casing 55 is similar to that previously described and shown in Figs. 2 and 3, with exceptions to be set forth.

A plurality of openings 56 are provided in the top of the casing as shown in Fig. 8, leaving spiders 51. A boss 58 similar to boss 18 of Fig. 3, is formed upwardly and which has a bearing member 59 threaded therein for the purpose of adjustment.

A cone shaped member 60, similar to that shown in Fig. 3, is welded or otherwise secured to casing 55 and having a flared diameter conforming to the diameter of the openings 56 as shown in Fig. 9. An air inlet conduit BI is secured to cone member 60 and connects the air pre-cleaner to the air cleaner in a manner similar to that shown in Fig. 1.

The bottom plate 62 is provided with spiders 63, a center portion 64, openings 65 and a rim 56. Holes are provided in bottom 62 and. a casing 55 to accommodate Wing bolts H, which serve to hold bottom 62 to casing 55. A boss 61 is formed at the center of plate 62 and a bearing member 68 is threaded into boss 61 to allow adjustments. Bearings 59 and 68 have V cen ters to provide journals for the rotor 28. This method of journalling has previously been de- 6 scribed and will need no further description. Openings 85 in this instance are provided with screen material l5 similar to that shown in Figs. 2 and 3 and need not be again described.

Bearing members 59 and 68 are so adjusted that rotor 23 will rotate as closely as possible to screen for the most efficient operation.

It will be noted that air entering screen will pass upwardly into air conduit 51 and then to the air cleaner similar to air cleaner A of Fig. 1. The air follows a path indicated by the arrows 69 of Fig. 9. The function of the modification shown in Figs. 8, 9 and 10 is identical to that of the air pre-cleaner shown in Figs. 1 to 7 inclusive and need not be further described.

It should be understood that the air conduit may be attached to the casing at any convenient location, for example at the side, or at the top or bottom and not necessarily co-axial, providing the function of the ore-cleaner is not interfered with. In locating the air conduit it should be kept in mind that air flowing through the screen must pass through the spaces 55 and impinge the vanes 33 in order to rotate the rotor.

The above being complete description of an illustrative embodiment of the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is:

An air pre-cleaner for connection to an air inlet conduit, in combination, a casing supported on said conduit and having a downwardly directed annular opening surrounding said conduit, a perforate member disposed in said opening, a rotor pivotally supported in said casing intimately adjacent and parallel to said perforate member, said rotor comprising a plurality of opposed discrete segments and means defining vanes associated with said rotor to impinge air passing through said perforate member causing said rotor to rotate, said segments substantially interrupting flow of air through said screen at successive points of rotation of said rotor.

SHERMAN C. I-IETH.

References Cited in the file of this patent UNITED STATES PATENTS Mulrhead Apr. 7, 1936 

